title: Application of an indicator based on taxonomic relatedness of ciliated protozoan assemblages for marine environmental assessment.
abstract: BACKGROUND
  Ciliated protozoa play important roles in aquatic ecosystems especially regarding their functions in micro-food web and have many advantages in environmental assessment compared with most other eukaryotic organisms. The aims of this study were focused on analyzing the application of an indicator based on taxonomic relatedness of ciliated protozoan assemblages for marine environmental assessment.
  
  
  METHODS
  The spatial taxonomic patterns and diversity measures in response to physical-chemical variables were studied based on data from samples collected during 1-year cycle in the semi-enclosed Jiaozhou Bay, northern China.
  
  
  RESULTS
  The spatial patterns of ciliate communities were significantly correlated with the changes of environmental status. The taxonomic distinctness (Δ*) and the average taxonomic distinctness (Δ+) were significantly negatively correlated with the changes of nutrients (e.g., nitrate nitrogen and soluble active phosphate; P<0.05). Pairwise indices of Δ+ and the variation in taxonomic distinctness (Λ+) showed a decreasing trend of departure from the expected taxonomic breadth in response to the eutrophication stress and anthropogenic impact.
  
  
  CONCLUSIONS
  The taxonomic relatedness (especially the pairwise Δ+ and Λ+) indices of ciliate communities are robust as an indicator with scientifically operational value in marine environmental assessment.
authors.affiliation: Laboratory of Protozoology, Institute of Evolution and Marine Biology, Ocean University of China, Qingdao, China. henglongxu@126.com
authors.forename: Henglong
authors.initials: H
authors.lastname: Xu
authors.forename: Yong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Khaled A S
authors.initials: KA
authors.lastname: Al-Rasheid
authors.forename: Saleh A
authors.initials: SA
authors.lastname: Al-Farraj
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
mesh_terms: D000818:Animals; D002681:China; D016798:Ciliophora / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D016770:Ciliophora Infections / Q000378:metabolism / Q000473:pathology; D002965:Classification / Q000379:methods*; D017753:Ecosystem; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D008386:Marine Biology; D018570:Risk Assessment / Q000379:methods; D013045:Species Specificity; D013696:Temperature